Telephone subset base



FIG. 1 is a perspective view of a telephone subset base showing my design;

FIG. 2 is a side elevational view thereof;

FIG. 3 is a front elevational view thereof; and

FIG. 4 is a top plan view thereof.

The broken line showing of pushbuttons in FIGS. 1, 2, 3 and 4 is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a telephone subset base, as shown. 